It was alleged that Ben Sulayem ordered race stewards to overturn a penalty given to Aston Martin's Fernando Alonso when he was on course for a podium.
The Spaniard had been hit with a five-second penalty for an incorrect start procedure but then was given another 10-second penalty after mechanics appeared to work on his car during the serving of the initial penalty.
It was that second penalty that the whistleblower had alleged that Ben Sulayem had tried to overturn, prompting anger among Mercedes, with George Russell coming home in fourth during that particular race.
FIA investigation result revealed
Russell did finish less than 10 seconds behind Alonso, meaning he may have claimed what would turn out to be a third podium of the season, and Mercedes team principal Toto Wolff revealed that he recalled the 'weird' situation.
Now, Ben Sulayem has been cleared of any wrongdoing, after an investigation by the FIA ethics committee.
The committee were also looking at separate allegations made by the same whistleblower that Ben Sulayem had told officials at the Las Vegas GP to find a way of passing the new street circuit as unsafe to race on, allegations the FIA president denied.
"After reviewing the results of the inquiries, the Ethics Committee were unanimous in their determination that there was no evidence to substantiate allegations of interference of any kind involving the FIA President Mohammed Ben Sulayem," the FIA said in a statement.